This invention relates to a cupola and more particularly to a cupola which receives part of its heat input from a plasma torch.
The plasma-fired cupola is a vertical cylindrical shaft furnace in which a plasma torch is fitted. The plasma torch and nozzle are described in a patent application entitled "Plasma Fired Feed Nozzle" filed May, 8, 1987 and assigned Ser. No. 047,811. The plasma torch advantageously provides some of the energy for melting scrap iron and steel independent of coke combustion. Utilizing this energy allows charging the cupola with material which would be blown from the bed if combustion of coke supplied all the energy. The plasma fired cupola also provides temperature, atmospheric and feed variations not permissible in regular cupolas.
An application entitled, "Replacement of Foundry Coke in a Plasma-Fired Cupola" filed May 8, 1987 and assigned Ser. No. 047,808 is related to this application and describes how other fuels can be substituted for coke and how fuel and alloying materials can be mixed.
An application entitled, "Control of Plasma-Fired Cupola" filed May 8, 1987 and assigned Ser. No. 047,810 is also related to this application and describes how the plasma-fired cupola is controlled.
A paper entitled "Test Results on a Pilot Scale Plasma Fired Cupola For Iron Ship Melting" was published by the inventor July 1985 and describes test results obtained when operating the cupola bus does not present the operating details disclosed hereinafter.
U.S. Pat. No. 4,530,101 entitled "Electric Arc Fired Cupola For Remelting Of Metal Chips" describe using plasma torches to melt metal chips being fed to the cupola via chip feed nozzles, but does not describe charging the cupola with metal chips.